You are writing an essay on how the indian dance known as kathak influenced the spanish flamenco dance, and you need concrete facts.

which is a concrete fact you could use in your essay and not an abstract assertion?
a) the spanish flamenco dance is a dramatic and romantic dance done by one man and one woman.
b) the indian kathak dance is often done solo or by groups of women all moving in sync with one another.
c) for years, historians and critics of dance have suspected that the spanish flamenco dance is actually derived from dances from india.
d) certain moves in the indian kathak dance--such as the quick turn and flip of hands held up high--are the same moves one finds in the spanish flamenco dance.

The correct answer is D) Certain moves in the Indian Kathak dance- such as the quick turn and flip- are the same moves one finds in the Spanish Flamenco dance.

Explanation:

This option can be considered a concrete fact because, as all facts, it can be verified by any person (contrary to a hypothesys for example, which needs to present facts to be proven correct and "existant"). Meaning, any person with eyes (or an acute sense of hearing) can verify wether the dance movements mentioned in the Kathak dance resemble or not those of the Spanish flamenco.

In the case of option C) for instance, wether historians and critics have suspected that the two dances are similar or not is an abstract assertion. There is no proof stated regarding which or how many authors have made said assertion, and thus it is considered a vague fundament.

Both, option B) and option A) are not facts that serve to support the hypothesis.